Home
Weather London
WeatherRadar
RainfallRadar
TemperatureRadar
WindRadar
LightningRadar
Weather News
Editor's Pick
Discover the app
Weather widget
Contact us
Apps
Career
    Home / Editor's Pick /

    Frosty mornings: When to scrape your car

10:30
29 November 2023

Frosty mornings
When to scrape your car

Hoar frost being easily scraped off a car windscreen.
Hoar frost being easily scraped off a car windscreen.

We all know that dreaded feeling of needing to get up early to defrost your car in the morning. But we have some tips to help you deal with it!

There are two main reasons that you car might need scraping when it's cold out, and that's because of a hoar frost, or frozen dew.

Hoar frost

Simply put, this is just what we usually call frost. It is the physical ice crystals that you can see on a sub-zero object or surface that has come into contact with moist air, as seen in the image above.

When the surface temperature falls below zero, and then below the dew point, the water vapour turns directly into ice as it cools and condenses on that surface.

Check out our video explainer on frost formation.

It's a white-ish sort of colour, and when you can just use the good old-fashioned windscreen scraper to easily get it off, that's definitely a hoar frost.

Frozen dew

Frozen dew on the other hand, will likely take you longer to get off your windscreen. It's a thin coating of glaze ice, and is what we are more familiar with, as black ice.

It forms in the same way as regular dew, but in a sub-zero environment. So, the surface temperature falls below the dew point first, allowing dew to form, and then falls below freezing. So the existing dew on the surface freezes over, and is awfully difficult to scrape off.

Sometimes you can have a layer of frost covering a layer of frozen dew beneath, which then just creates double the work!

It's often in this case that people are tempted to bring out their kitchen kettles. Whilst modern windshields are strong, they can still crack and the seals can deteriorate faster when subject to rapid temperature changes, so avoid this!

Instead, we suggest a de-icer spray, or a pre-ice spray. Alternatively you can mix up a concoction of three parts vinegar and one part water, which should keep your screens frost-free by morning. Covers can also do the trick.

But how do you know when to do all of this? Well, just be sure to keep an eye on the TemperatureRadar and our top weather tips to know when a frost is likely.

Weather & Radar editorial team
More on the topic
Half of England now in drought. Joining North Wales. . . Wednesday, 29 July 2026
Dry section of the River Thames beneath a small stone bridge, with the riverbed exposed and cracked after prolonged, dry weather, while a person walks along the roadside above.
Wednesday, 29 July 2026

Joining North Wales

Half of England now in drought
Forest fires spread to south-east Europe. Heat and strong winds. . . Thursday, 30 July 2026
Split image showing an active wildfire with flames and thick smoke on the left, and a wind forecast map of Greece on the right with gusts of 25–35 mph around the Aegean Sea, alongside a wildfire warning symbol highlighting elevated fire danger.
Thursday, 30 July 2026

Heat and strong winds

Forest fires spread to south-east Europe
June records rise after verification. Multiple new highs. . . Thursday, 30 July 2026
Temperature map of the UK and Ireland highlighting verified June temperature records, with 38°C in England, 35.1°C in Wales, and 30.8°C in Ireland. A large thermometer icon emphasizes record-breaking June heat across the UK.
Thursday, 30 July 2026

Multiple new highs

June records rise after verification
All weather news
This might also interest you
Seasonal warmth between spring thunder. Your weather - Your shots. . . Sunday, 19 April 2026
Split image showing coastal sunset with layered lenticular clouds over rooftops and palm trees on the left, and a green valley with river and hills under soft daylight on the right.
Sunday, 19 April 2026

Your weather - Your shots

Seasonal warmth between spring thunder
Flooding, gales, and heavy snow. Storm Chandra. . . Tuesday, 27 January 2026
Split image showing aerial flooding in a town with muddy water covering roads on the left, and a rural road on the right blocked by heavy snowfall with vans stopped and a person walking in snow.
Tuesday, 27 January 2026

Storm Chandra

Flooding, gales, and heavy snow
Long-term trends need a pinch of salt. 40 °C in July?. . . Tuesday, 30 June 2026
Temperature radar of 2022 heatwave where the all-time temperature record in the UK was set. Warning symbol overlain.
Tuesday, 30 June 2026

40 °C in July?

Long-term trends need a pinch of salt
All articles
Weather & Radar

Weather & Radar is also available on

Google Play StoreApp Store

Company

Contact us Privacy Policy Legal info Accessibility statement

Services

Uploader

Socials

facebooktwittertikToklinkList